<!DOCTYPE html>
<html lang="en-US">

<head>
  <meta charset="utf-8">
  <title>图片</title>
</head>

<body>
  <header>
    <ul>
      <li><a href="index.html">Home</a></li>
      <li>Pictures</li>
      <li><a href="projects.html">Projects</a></li>
      <li><a href="social.html">Social</a></li>
    </ul>
  </header>
  <main>
    <img srcset="images/search-794px.jpg 794w,
                images/search-640px.jpg 640w,
                images/search-480px.jpg 480w" sizes="(max-width:340px) 320px,
                (max-width:500px) 480px,
                (max-width:660px) 640px，
                794px" src="images/search-794px.jpg" alt="搜索框图片">

  </main>
</body>

</html>